What RPG does the most with the least words?
Visit the Pocketmod Games community on G+, there are some great designers doing some phenomenal stuff within that format. I've probably seen more innovation there than in most other
parts of the RPG community, and I'm not just saying that because I moderate that particular community.
Otherwise, I'd be pointing back at the muse of a game GHOST/ECHO which has informed a lot of my design work since it's release. Many people have referred to John Harper's other minimalist game, Lady Blackbird, but for sheer minimalism of text and impact-per-word I have to sat GHOST/ECHO is far higher on the scoreboard.